Britt Reid has just formally entered a guilty plea to felony DWI in his car crash case after cutting a deal with prosecutors ... and the attorney for the victims tells TMZ Sports they are not happy with the situation.
The former Kansas City Chiefs assistant coach -- wearing a suit with a yellow tie -- made the plea during a hearing in a Missouri courtroom on Monday morning ... nearly two years after he was accused of getting drunk and then causing a car crash that severely injured a 5-year-old girl.